Not Applicable
Not Applicable
1. Field of the Invention
This invention relates to a locking mechanism for securing the cover of a thin-walled box to a box frame. More particularly, the invention pertains to a lock for a ringless electrical meter box.
2. Description of the Prior Art
By way of background, utility companies provide and regulate power usage with the aide of metered fuse devices (meters). The meters allow power to run to individual customers and record the amount of power used by each customer. A typical electrical meter has rear electrical contact prongs that plug into electrical receptacles connected to a current transformer switch located inside a metal meter box that is situated individually or ganged with other meter boxes. In a ringless meter box, the meter is secured within the meter box by a hinged meter box cover having a flanged, circular opening through which the meter protrudes when the box cover is shut. The meter box prevents tampering with the meter and provides a means of disrupting or discontinuing service when necessary, whether for lack of payment by a customer or when service is no longer needed. This is done by removing the meter and covering the opening in the meter box cover, or by rotating the meter such that it does not contact the electrical receptacles, or by placing insulator plugs over the meter""s electrical contact prongs. To prevent the reactivation of service by way of a replacement meter or a jumper placed across the meter box electrical receptacles, the meter box needs to be secured by tamper-proof means, such as a lock located on the exterior of the meter box, which prevents opening of the box cover. In addition, because of possible hostile conditions (e.g. dogs, disgruntled customers), service personnel should be able to secure the meter box as quickly as possible. Relatedly, it should be possible to mount the lock at different locations on the meter box even though the box wall profile differs from one location to the other. Presently, a variety of ringless meter box locks are used. Most need to be placed at predetermined positions, or require that a hole be drilled in the meter box 3. Others require the use of manually adjustable components and/or need keys and tools for installation. These locks are thus relatively time consuming to install. In addition, they may require that a hand be placed within a live box during installation.
The foregoing problems are solved and an advance in the art is obtained by a novel locking mechanism for securing the cover of a thin-walled box to a box frame. The locking mechanism comprises a clip bracket adapted to engage a wall of the box frame, a lock body adapted to latch to the clip bracket and engage the box cover, a locking member carried by the clip bracket and adapted to clamp the clip bracket to the box wall when the locking member is in a clamping position, and a pivotable actuating lever adapted to actuate the locking member into the clamping position.
The clip bracket can be configured with an outer catch portion adapted to extend outside the box frame and receive the lock body, an inner lever-carrying portion adapted to carry the locking member and the actuating lever within the box frame, and an intermediate throat portion interconnecting the catch portion and the lever-carrying portion. The throat portion is preferably sized to accommodate box walls having lips or flanges so that the locking mechanism can be mounted at the bottom of a ringless meter lock box (which typically has an inwardly extending lip or flange) as well as the sides thereof.
The lock body mounts a spring-loaded plunger lock assembly that is preferably configured for keyless slam-lock engagement with the catch portion of the clip bracket to facilitate quick installation. A slotted opening in the lock body receives the catch portion into engagement with the spring-loaded plunger lock assembly. The spring-loaded plunger lock assembly seats within the lock body in a manner that prevents removal of the plunger lock assembly by unauthorized means. A key configuration on the plunger lock assembly is provided for releasing the lock body from the clip bracket via a key. The key configuration is designed to prevent unauthorized release of the spring-loaded plunger lock assembly using a tool or device other than the key.
The locking member and the actuating lever can be implemented as a two-piece system comprising first and second pivoting members. Alternatively, the locking member and the actuating lever can be integrally formed as a one-piece system. In the two-piece implementation, the actuating lever is adapted to be manually pivoted into actuating engagement with the locking member prior to closure of the box cover. The actuating lever can be formed so that a cover-engaging portion thereof is trapped between the box cover and the clip bracket when the box cover is closed. This all but eliminates the possibility of the actuating lever being pivoted out of engagement with the locking member should an attempt be made to dislodge the locking mechanism by unauthorized means. The actuating lever also has a locking member-engaging portion, which can be implemented using a cam configuration, to contact a face of the locking member and urge it into the closed clamping position. Advantageously, the cam is shaped to retain the locking member in the clamping position irrespective of box frame orientation or box cover closure position. In the one-piece implementation, the actuating lever and the locking member pivot as a unit. The actuating lever is then preferably formed with a cover-engaging portion that is contacted by the box cover when it is closed. As this occurs, the actuating lever will be pivoted, thereby also pivoting the locking member into clamping engagement with the box wall. The cover-engaging portion of the actuating lever will also serve to convert any prying force on the locking mechanism or box cover into increased clamping force.
Advantageously, no drilling is required to install the locking mechanism. The clip bracket is simply placed over the box wall, the actuating lever is positioned as necessary, the box cover is closed, and the lock body is secured to the clip bracket.